This invention relates generally to mounting arrangements for rotating machines and more particularly to a resilient mounting arrangement adaptable to varying size bases and therefore particularly suited for an aftermarket or replacement motor mounting arrangement.
A commonly used resilient mounting arrangement for rotating machines, such as fractional horsepower motors, utilizes a pair of cushion rings disposed on hubs at opposite ends of the motor and engageable with corresponding cradle portions of a U-shaped cradle base with the rings being clamped to the pertaining cradle portions or arms of the base. The resilient rings themselves may be toroidal in form or may be axially slotted, fluted or otherwise irregularly configured around their inner or outer periphery to prevent rotation of the machine relative to the mounting base, for example due to starting torque of the machine. Regardless of the peripheral configuration of the mounting rings, such rings are typically located in a fixed axial position for engagement with the arms of the associated machine mounting brackets.
In the fractional horsepower motor industry there is little uniformity in the dimensions of the cradle bases and motor replacement frequently requires replacement of the cradle base along with the motor or extensive stocking or searching for an appropriate replacement motor to fit the existing base.
One approach to providing a replacement motor to fit a number of different size cradle bases has been to provide motor through-bolts of a length in excess of that required to pass from one end shield to the other and to clamp, for example, between a pair of nuts on each such extended through-bolt, a bracket arrangement for supporting a resilient mounting ring. Such a bracket and ring might be complementarily contoured to prevent relative rotation, however, the axial position of the mounting ring relative to the bracket is fixed and to adjust the bracket to suit a particular cradle base requires the loosening and retightening of pairs of nuts on each through-bolt. The adapting of such an arrangement to a particular cradle base is therefore somewhat time consuming and the structure itself adds to the cost of the motor.
Due to the variations mainly in axial length of such motors, replacement motors are frequently sold with a U-shaped cradle base attached thereto and the provision of a replacement motor easily adapted to a variety of existing bases would elminate the base cost from the cost of the replacement motor as well as easing the burden of removing the old base and installing the new base at the time of replacement.